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<head><title>11-712 NLP Lab</title></head>
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<h1 align=center>Language Technologies Institute<br>11-712: Self-Paced Laboratory</h1>

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<h1>Algorithms for NLP:<br>
GLR Parsing Module</h1>

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<td valign=top><b><i>Objective:</i></b></td>
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The Generalized LR Parser, implemented by Masaru Tomita and extended
by other researchers, has been the basis for natural language analysis
in several applied projects at CMU. In this module, you will work with
the GLR parser to gain experience with basic issues which are
typically addressed in each practical application.  As part of this
module, you will complete the following tasks:

<ul>
<li>Write a small syntactic lexicon;
<li>Write a small semantic lexicon;
<li>Write lexical lookup functions for the two lexicons;
<li>Debug/extend a given grammar to extend its functionality;
<li>Write a grammar callout function to implement semantic restrictions.
</ul>
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<td valign=top><b><i>Background<br>Material:</i></b></td>
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         <i>The Generalized LR Parser/Compiler Version 8.1: User's Guide</i>,
         Masaru Tomita (ed.), Teruko Mitamura, Hiroyuki Musha and Marion Kee.
         CMT Technical Memo, April 1988.<p>

       "Coping With Ambiguity in a Large-Scale Machine Translation
       System", Baker, Franz, Jordan, Mitamura and Nyberg, Proceedings of
       COLING-94.<p>

<i>Copies of this material will be available in the LTI Lab (CyH 277).</i>
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<ol>

<li>Read the first background reading to familiarize yourself with the
GLR parser, especially the syntax of the grammar rules. 
</li><p>

<li>Read Section 4 in the second background reading, to familiarize
yourself with the the notion of semantic restrictions on attachment
during syntactic parsing.  </li><p>

<li>If you have any questions after reading the background materials,
seek guidance from the instructor.</li><p>

<li>Follow the <a href="instructions.html">step-by-step
instructions</a> to complete your program and data files for the
module. </li><p>

<li>Hand in your files (<code>glr-lexicon.lisp</code>,
<code>glr-semantics.lisp</code>, <code>glr-grammar.gra</code>, and
<code>glr-code.lisp</code>) by copying them to the directory
corresponding to your userid under:

<p align=center>
/afs/cs/project/cmt-55/lti/Lab/Modules/NLP-712/handin/</p>

<p>Also include a file called <code>test-output.txt</code>, containing of
a transcript of your code running on the given test data (see the
<a href="instructions.html">instructions file</a> for more details).</p>

<li>Notify the instructor that your module is ready for
evaluation. Please be sure to check that you have completed all the
parts, and that you have created the 5 files mentioned above, with the
precise names given, before handing in your work.</li><p>

</ol>

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<i>5-Nov-96 by ehn@cs.cmu.edu</i>

